Colloquium – Colin Burke

Colin Burke, University of Illinois- Urbana-Champaign

Probing the Invisible Universe with Variability

The Vera C. Rubin Observatory will imminently transform time-domain astrophysics by enabling precision, long-baseline optical variability measurements for billions of sources. Time-domain variability provides a uniquely powerful window into the otherwise invisible components of the Universe, from the physics of accreting black holes to the nature of dark energy driving cosmic acceleration. In this talk, I will present several projects that leverage optical variability to address fundamental open questions in astrophysics and cosmology. First, I will show how variability-selected active galactic nuclei (AGN) in low-mass galaxies can be used to identify the elusive intermediate-mass black holes (IMBHs) and discriminate between competing models of supermassive black hole formation and growth. I will then discuss how stochastic variability encodes key aspects of accretion physics, offering new empirical constraints on black hole mass, accretion state, and disk structure, including insights into the nature of the enigmatic “little red dots.” Finally, I will demonstrate how AGN variability can be standardized to construct independent distance indicators, enabling new probes of dark energy and the expansion history of the Universe.

Bio: Dr. Colin Burke is an NSF Astronomy & Astrophysics Postdoctoral Fellow in the Department of Astronomy at Yale University. His research focuses on variability of active galactic nuclei as a probe of supermassive black hole formation and evolution, the population of intermediate-mass black holes, and accretion. He completed his PhD at the University of Illinois Urbana-Champaign in 2023.

February 23, 2026 @ 3:00pm (CST) in 4309 Stevenson Center

Host: Steve Taylor